Burner



May 23, l944 J. A. WHITTINGTN v2,349,323

BURNER Filed April 8, 1940 d T C type.

Patented May 23, 1944 UNITED STATES PATENT OFFICE BURNER James A.Whittington, Evanston, lll.

' Application April `8, 1940, Serial No. 328,413

- 1 Claim.

The present invention relates in general to burners and is particularlyconcerned with an im` proved gas burner of the type generally known as aBunsen burner.

Heretofore, burners of this type were of such design and operated insuch manner that the burners had to be constructed of diiiere'nt sizesand dimensions for each type of gas with` which the burner was to beutilized. v'I'hat is, if aburner, for example, were to be utilizedfor'the burning of a gas having a comparatively high B. t; u. contentsuch as iso-butane, the burner in order to operate efficiently had tohave its parts relatively so proportioned ras to size as to provide theproper mixture for this particular gas, whereas for a gas such as theso-called mixed gas hav-Y ing a relatively low B. t. u. content adifferent size burner with parts of different sizes and proportions wasnecessary. Due to the difference in sizes in the burners required forthe different gases with which the burners might be utilized; it washeretofore necessary for the burner manu# facturer to build or theburner supplier to provide y a plurality of burners of different sizes,`thus materially increasing the cost of manufacture and the cost ofstocking the burners.

The present invention broadly contemplates an improved burner of suchconstruction and design that the size of the burner may be standardizedirrespective of the particular gas utilized in the burner. To this end,in 'my improved burner, the mixing chambers and air inlet openings arestandardized as to their relative proportions and may be used withoutchange for all the gases commonly available for burners of this The sizeof the gas inlet orice is the only part which is varied in my burner toadapt it for use with a particular one of the available gases.

'I'his construction is of tremendous advantage from the standpoint ofthe cost of manufacture and inthe maintenance of burner stocks. Theburner may be initially fabricated, without a gas orifice, as a simplestandardized stock item or unit available for use with any of the usualgases. All that is then vnecessary to commission the burner for use witha particular gas is to provide the stock unit with an orifice of properpredetermined size depending upon the particular gas With which theburner is to be utilized. Since this orifice is in the form of a roundpassage, it will require but one simple operation to commissionthe'burner for use with any one'of the gases, and this commissioningoperation may be simply accomplished by means of a proper size drill.

, Moreover, a burner embodying the features of G5 construction of myinvention having a standard size and overall dimension for utilizationwith thedifferentgases is further advantageous in that `it may be mosteiciently utilized inboilers, refrigerators, and other commercial andindustrial! applications. For example, sucha burner enables the use of astandard mounting to provide the most eilicient spacing between 'theburner tip and the surfaceof the body being heated, thus making itunnecessary to vvary this distance for diiferent'installation conditionswherein different gases may respectively be utilized.

VIt Yis a`further object of the herein described invention to provide animproved burner construction which will operate with extremely highefficiency; which will be free from back-iire, carbonization and otherundesirable operating characteristics; and in which the various parts ofthe burner.1are relatively so proportioned in such novel manner as tomaintain a practically constant air-'gasratio during variation of thegaspressure over a wide range, a feature which was "heretofore thoughtcould only be attained in a burner with aVenturi type of mixer.

,It is a further object of the present invention to provide an improvedburner construction adjacent the eiiluX end of the gas admitting orificefor the collection of dirt, lint and other foreign matter to keep itfrom occluding the orifice, particularly under operating conditions inwhich the gas may be admitted at a comparatively low pressure. I i Afurther object of the invention is to provide an improved constructionat the combustion end of the burner tip for facilitating'the successivelighting off of a plurality of adjacently disposed burners from eachother after one of the burners has been lighted.

A still further object of the invention is to provide an improved methodof making or constructing a gas burner.

Still another object is "to provide an improved method of burningvarious gases in a single burner of the herein described type.

Other objects and features` of the invention will more fully appear fromthe following detailed description taken in connection with theaccompanying drawing, which illustrates a single embodiment thereof, andin which:

Figure 1 is a vertical longitudinal sectional view through a burnerconstructed in accordance with the features of the herein describedinvention;

Figure 2 is-a plan view of the same; v

Figurey 3y is a1 fragmentary view in elevation looking toward the airinlet opening of the burner;

Figure 4- is a transverse sectional view taken through the burner at theposition of the air inlet opening, taken substantially on line IV-IV ofFigure 1;

Figure is a fragmentary sectional view showing an alternativeconstruction at the efux end of the burner gas orice; and

Figure 6 is a fragmentary sectional view showing an alternativeconstruction at the combustion end of the burner.

As shown on the drawing:

As illustrative of the burner of my present in vention, I have selecteda construction as shown in detail on the drawing, this constructionembodying the features of operation and utilization as will hereinafterbe disclosedin detail.

In general, the burner of the present invention embodies an elongatetubular body as generally indicated at I0 which maybe constructed of anysuitable material such as brass, bronze and vthe like. The lowermost endof the burner body is tapered and threaded as shown at II to enableconnection of this end to a suitable gas supply for the burner. Theopposite end is in the form of a contracted tubular portion I2 which ispreferably integrally formed with the body of the burner. Intermediatethe ends of the burner, the body is preferably formed with a polygonalouter surface for receiving a suitable wrench or tool., whereby theburner may be rotated during its connection to a suitable base or othersupporting structure through which gas may be supplied to the burner.

Anelongate tubular sleeve I3 isdisposed with its lowermost end marginsurrounding the tubular extension I2, the lowermost end of the sleevebeing in abutting relation with a peripherally extending abutmentshoulder I4 at the lowermost end of the extension I 2 where theextension joins the burner body. The sleeve I3, it will be noted,

chamber I'I at its uppermost end communicates with a second stageexpanding or mixing chamber I8 which is in axial alignment with the rststage chamber.

It will be noted that the juncture of the rst and second stage chambersis connected by an abrupt shoulder or surface I9 which acts to set upeddy currents or a certain amount of turbulence as the combustiblemixture passes from the rst stage chamber to the second stage chamber,thus materially enhancing the mixing of gas and air before it reachesthe opening I5 at the uppermost end of the sleeve I3.

The lowermost end of the burner body is provided with a central bore orpassage 20 for gas which leads to a gas orice or nozzle 2| of tubularform and predetermined cross-sectional area, as will later-be describedin detail.

Thev gas eillux end of the nozzle is centrally disposed at the lowermostend of the chamber II.

In order to supply air or other-supporter' of combustion to the gasissuing from the orifice 2 I', the body of the burner is provided with alaterally cut slot 22 which extends into the lower end of the chamber I1and is adjacent to or proximate to the discharge end of the gas orice.The bottom surface or oor 23 of this slot is preferably even or levelwith the discharge end of the orice as shown.

While the foregoing describes in a general manner, the construction ofmy improved burner, it has been found that in order to successfullyoperate the burner and e'iciently 'burn the combustible mixture of gasand air and prevent backfring of the burner, the air inlet, mixingchambers and the gas orifice must be proportionedas to length, size,etc. in a very denite relationship.

In determining the relationship and-proportions between the variousparts of my improved burner, the combustion constants of the variousgases have been taken into consideration and are listed in the followingTable A:

TABLE A Air Lbs. of Theo- Gas B t u Cu. ft. gas Lbs. gas lf'gg'gg airretcal Std. Area pressure, Gas Sp. gr. per 'c 'it required] required]bastion required area of d rill ol inches B.t.u. 2 B.t.n. pounds per per3200 orifice size orice water pound gas B.t.u.

Methane 0. 5543 1, 014. 7 3. 153 0. 13378 17. 274 2. 3109 001096 001 3,1 Ethane. l. 0488 1, 781. 0 1. 797 0. 14428 16. 132 2. 3278 .000624 70/.00062 5.8 Propane. 1. 5617 2. 572.0 1. 240 0. 14834 15. 712 2. 3307.000431 74/. 00040 8. 7 Iso-bu tane. 2. 0665 3, 251.0 0. 9843 0. 1567215. 495 2. 4283 000342 75/. 00035 1l. 5 N-butane.. 2. 0G65 3, 353. 0 0.9544 0. 15099 15. 495 2.3396 000342 00035 11. 5 N-pentane 2. 4872 3,981.0 0. 8038 0. 15304 15.366 2. 3516 000279 77/. 00025 13.8 N-hexane 2.9704 4, 667. 0 0. 6857 0. 15593 15. 275 2. 3818 000238 77/. 00025 16. 5Ethylene. 0. 9740 1, 631.0 1. 9620 0. 14829 14.820 2. 1977 000682 69/.00070 5. 4 Propylene. 1. 4504 2, 336. 0 1. 3656 O. 15158 14. 820 2. 2464000475 73]. 00045 8. 1 Butylene 1. 9336 3, 135.0 1. 0207 0. 15106 14.8202. 2387 000355 75/. 00035 10. 7 Acetylene 0. 9107 1, 503.0 2. 1290 0.14841 13. 306 l. 9736 000740 69/. 00070 5. 1 Benzene. 2. 6920 3, 741.00. 8554 0. 17621 13. 306 2. 3247 000297 76/. 00031 15.0 Toluene. 3. 17604, 408. 0 0. 7259 0. 17646 13. 535 2. 3884 .000252 77/. 00025 17. 7Mixed. 0. 540 800 4.000 0. 16535 13. 785 2. 2793 .00139 58/. 00139 3.0NaturaL. 0. 675 1, 039 3. 0. 16018 14. 631 2. 3392 00107 63/. 00108 3. 0

extends an appreciable distance beyond the outermost end of theextension I2 to define an outlet I5 at the uppermost end of the sleeve.The uppermost end of the sleeve I3 is preferably provided with a chamferI 6 or similar bevel to aid in the inflow of air to the burner flame forsupporting combustion thereof at the opening I5,

In the construction shown, the body IIJ of the burner and the extensionI2 cooperate to dene an elongate tubular passage or bore I1 whichconstitutes a first stage chamber for the mixing of air and gas admittedto the burner.'

The

It is generally well known that the Weight of air required to liberate aB. t. u. from a gas is, for all practical purposes, substantiallyconstant for the different gases, and, that as between gases havingdifferent B. t. u. contents the amount of air required for combustionwill be proportional to the B. t. u. contents of the respective gases.

By reference to Table A, column 5, it will be noted that the Weight ofgas for a given B. t. u. content is substantially constant. With aknowledgev of the foregoing relationships, it can be shown thattheweight 'of air required for the combustion of Vquantities of thevarious gases sufcient to liberate a desired or given heat value issubstantially constant.' This constancy is shown in Table A, column 7.

The commercial gases available for use with burners of the hereindescribed type are usually composed of the combustible gases listed inTable A, either singly or in various proportions, together with inertgases such as carbon dioxide and nitrogen, and a small amount of oxygen.Since the weight of air required to liberate a given heat value from thevarious gases is substantially constant, as previously pointed out, ittherefore follows that the weight of air required for mixtures of thesevarious gases to liberate the given heat value, will remainsubstantially the same as for that of only one of the gases.

It will therefore be apparent that with these substantially constantfactors in the various gases, if 'the air inlet opening to the burner ismade of such size as to be capable of Vadmitting the required amount ofair for combustion, the size of this opening may be made constant and offixed value irrespective of the gas which is being utilized, providedthe gas orice and gas pressures at the manifold are properly determined.Since the rate of admission or injection of the air into the gas isknown to be a function of the gas momentum as it issues from the gasorifice, it is therefore possible to provide an orifice of proper sizeto admit the required amount of gas to liberate whatever B. t. u. perhour'heating effect may be desired, for example, 3200 B. t. u, per hour,and that by utilizing the proper gas entering pressure, the momentum ofthe gas stream may be maintained substantially constant.

When the proper size orifice and gas pressure are determined, no otherchange in the burner design is necessary for satisfactory operation witha particular gas. It will therefore be apparent that with a burner ofproper design, the mixing chambers and the air inlet opening may beconstant factors in the burner, and the only variable in the burnerconstruction is the size of the gas orice.

By way of a specic example, a burner designed to liberate 3200 B. t. u.per hour when a gas is burned therein, will have the dimensions asindicated in the following Table B:

TABLE B Burner parts Dimension In general, it will be noted that withthe above dimensions the cross-sectional areas of the first stagechamber and the second stage chamber will be in the ratio ofsubstantially one to two, that the first and second stage chambers areof sub- 'stantially the same length and that the air inlet interiorcircumference of the rst stage mixing.

the slot'will therefore extend a substantial 'distance past. the eiiiuxend of the gas orifice.

Since the dimensions of the burner as given in Table B are of constantdetermination irrespective ofthe gas with which the burner is to beused, the burnerwill :have constant overall dimensions; The burner maytherefore be constructed as a standard unit or stock item, without anorifice therein, and may subsequently be commissionedat any time desiredfor use with a particular gassimply by drilling the proper size orice;as shown in Table A, column 9. Column l0 shows the proper gas pressureto be used in each case with the burner for the particular gas for whichthe burner has been commissioned, regulating means being providedusually at the place of installation so that the gas pressure may beregulated to the desired value.

For example, if it is desired to burn 3200 B. t. u. per hour of 800 Bvt. u. mixed gas, the burner would have an orifice with across-sectional area of ..00138sq; inch, such as would be produced by astandard No. 58 drill, and the proper gas pressure to utilize at themanifold would be 3 inches water column. AAs initially constructed, thebore 20 is closed by a partition relativeto the first stage mixingchamber. Thus, when it is desired to commission the burner for aparticular gas,` all that is necessary is to drill an opening of propersize through this partition to form a gas orifice interconnecting thebore 20 with the rst mixing chamber.

Since the amount of air inspirated into the gas is dependent' upon themomentum of the gas leaving the orifice, the air-gas ratio remainssubstantially constant for the various gases with changes in theirpressure.

In the following Table C, I have shown the air-gas ratio for a burner ofthe present invention when utilized with an 800 B. t. u. mixed gas:

TABLE C Air-gas ratios [800 B. t. u. mixed gas] Psffse Gas Per centAir-gas Per cent water rate gas ratio air It will be noted from theabove table that the gas pressure may be varied over a wide rangewithout materially affecting the air-gas ratio. A very eicient burnertherefore results in which complete combustion will take place, andbackring, blowing from the ports, and other undesirable operatingcharacteristics will be eliminated.

Referring to Figure 5 of the drawing, I have disclosed an alternativeconstruction at the efux end of the burner gas orifice. In thisconstruction instead of making the floor 23 of the air admitting sloteven or level with the discharge end of the orifice as shown in Figure1, the portion of the floor lying within and adjacently surrounding theorifice is provided with an annular groove or recess 24. This groove orrecess forms a downwardly extending extension of the first stage chamberand does` not-interfere Withthe eflicient operation of the burner, theoutlet end of the orifice being retained as before at the floor level ofthe air inlet slot. This alternative construction is particularlyadvantageous, When-the burner is utilized with low gas entrancepressures, as 'it prevents the accumulation of dirt, lint and otherforeign matter at the orifice, which might otherwise occlude the orificeand aiect its proper functioning. This construction is especiallydesirable. when the burner is to be utilized as a pilot light.

In Figure 6, of the drawing, I have shown an alternative construction inwhich the uppermost end of the sleeve I3 instead of beingprovided withan outside chamfer I6 is provided With` an inside chamfer as shown at25. This arrangement gives a slight flare to the burning flame and isespecially advantageous in that it facilitates the successive lightingoff of a plurality of adjacently mounted burners one from the other,after one of the burners has been lighted.

While in the disclosed burner construction, I have shown the first andsecond stage mixing chambers as being formed of separate parts, it willbe readily` appreciated that the extension l2 and'sleeve I3 may, ifdesired, be integrally formed of one piece.

liti is thought that the. improved method of constructing a burner ofthis type, as Well as the improved method of burning a gas in suchburner will be readily apparent' from the foregoing description of myimproved burner.

lF'rorn thev foregoing description, it will be apparent that the presentinvention provides an improved burner of the Bunsen type which may beinitially provided as a standard unit with xed dimensions; which may bereadily commissionedfor use with any one ofl a plurality of differentgases merely by providing a proper sized orifice as determined by theparticular gas for which the burner is to be utilized; which Willoperate with high efficiency, is free from backfire, carbonization, andother undesirable operating characteristics; a burner in Which thevarious parts thereof are relatively so proportioned as to main tain apractically constant air-gas ratio during variations in gas pressureover a Wide range; which is so arranged as to facilitate the successivelighting off of a plurality of adjacently mounted burners, when one ofthe burners has been lighted; which utilizes a novel construction inwhich occluding of the burner gas orifice by foreign matter iseffectively prevented, especially at low gas pressures; which embodiesan improved method of making a gas burner; and which utilizes animproved method for burning of the gas.

It is of course to be understood that although I have described indetail a preferred embodiment of my invention, the invention is not tobe thus limited, but only insofar as defined by the scope and spirit ofthe appended claim.

I claim as my invention:

A burner comprising a body member having an elongate passage open at oneend and a gas orifice at the other end thereof, and an air ad.- mittingslot in said body at the junction of said orifice and passage extendingpartially through the body from one side thereof With its inner endterminating between the longitudinal axis of the body and the oppositeside thereof.

JAMES A. NHITTINGTON.

